Hi there,
I'm pretty crap when it comes to finger drumming, but the other week I came across Melodics - which is sort of an educational video game which lets you practice finger drumming like Guitarhero. Appearantly it's been around for a year, but I haven't seen it mentioned here when using the search function so I thought I'd share it. (no affiliation). http://www.melodics.com

The first 20 lessons (or so) are free, thereafter it's a subscription model whose priceworthiness sort of depends on your determination to practise. 10 or 20 bucks a month. I believe you need some midicontroller to do it, if you are not drumming Qwerty. I run it on a Mac with Ableton Push 1, it has on some occasions freezed up on me. But it's quite addictive and fun.

So, as I said I'm pretty crap but I believe I have made some progress now running through the free lessons. So, I think I might subscribe for a month just to see if it's fun to keep it as a daily ritual.

Worth a try!

no Linux version....